customizes a global operation for mybatis-plus , and then returns null all the time.
when I was customizing the sql injector class, I suddenly found that existsById () had been selling short pointers all the time, so I looked at the results and found that I always returned null .
well, developers say they want to define the return value when using addSelectMappedStatement () . They have been looking at the table data all the time. They really haven't noticed that they still need to define the return value type
mybatis-plus-sql-injector
although it is only a small mistake, let's record it here. After all, stepping on the pit once is enough.
1. The current table structure partition is . the main table is an and contains the necessary underlying data. from the table: B, c, d, e, etc. related tables: ab, ac, ad, ae, etc. now the data sent from the front end is a string of json string...